7. Вычислите: \(\frac{5}{6}+\left(2-1\frac{23}{35}\right):\frac{9}{25}-1\frac{2}{7}\).

\[2-1\frac{23}{35}=\frac{70}{35}-\frac{58}{35}=\frac{12}{35}.\]

\[\frac{12}{35}:\frac{9}{25}=\frac{12}{35}\cdot\frac{25}{9}=\frac{20}{21}.\]

\[\frac56+\frac{20}{21}-\frac97=\frac{35}{42}+\frac{40}{42}-\frac{54}{42}=\frac{21}{42}=\frac12.\]

Ответ: \(\frac12\).